I'm surprised by your response.. you've progressed much of controlling and taming your own ego... 
For that specific question, it's a question that you need to seek out yourselves and eventually you will find the answer of that question.. yourselves..
Its may b due to the thoughts regarding re-incarnation.
But i have more thoughts, something kinda strange and also bit difficult to make someone else understand. Anyway i ll share it perhaps it will open new ways of thinking..
So experience the non-existence is same like a self in all space time the day since the self manufactured untill its expiry or may b the self can never expired..
Self use things that can expired and have their life like human body..
By self you can suppose/assume/assign anything to it like a conscious/character/soul/human with barcode xyz etc etc..
I m coming to the main point of my thought ATM in time/space..
Non-existence and existence both exist at the same time and in everytime..past present future..
We existed always. Even if our parenrs decide not to bring a new body to world. The self was searching another body from another human so at this point its not about body but about our own soul CODE.
CODE can only exist in one body at one time we are a CODE that was always present thinking about non-existence as well as existence both are the sides of same coin. CODE switch them from. Time to time... Example is like this this
100 years ago..... Code was there (UNABLE TO LOCATE)
Present..... We know who is and where is code...
100 Years after.... Code will be there..... (UNABLE TO LOCATE)
The border line between past and future is like death and birth..
Its a long topic perhaps need another seperate thread. I m not sure if you are understanding basically i m trying to saying everyone ( was is will) present everytime.
Original Question become more tricky loop can go back to previous cycles and so on like before 13.7 billion years there were more cycles of creation of universes even if u come out from time illusion the creator behind all this sometimes mind just get hang like a mobile/latop when encountring a deep heavy programe. My mind drives me crazy sometimes